James j



(No Model.)

J. J. BRADLEY.

INGANDESGBNT LAMP soGKBT. No. 425,741. Y Patented Apr. 15, 1890.

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ms noms wenn; no., maro-urna.. wuumurun n L UNITED STATES PATENT OEEIOE. I,

JAMES J. RRADLEY, OE HARRISON, NEW JERSEY, ASSIGNOR TO rrI-IE EDISON LAMI COMPANY, OE SAME RL'AOE.

INOANDEscI-:NT-LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 425,741, dated April 15, 1890.

Application filed October 18, 1889. Serial No. 327,442. (No model.)

To all whom t may concern:

Be it known that I, JAMES J. BRADLEY, a citizen of the United States, residing at Harrison, in the county of Hudson and State of 5 New Jersey, have invented a certain new and useful Improvement in Sockets for Incandescent Electric Lamps, of which the following is a' specification.

My invention relates to that class of sock- Io ets or holders forincandescent electric lamps in which the socket is provided with an internally-screw-threaded metal sleeve for receiving the base of the lamp, such base being provided, as is now well understood, with an I 5 externally-screw-threaded metal 'band engaging with the sleeve of the socket and making mechanical and electrical connection between the lamp and the socket.Y WVith devices of this character difliculty has arisen in zo places where the lamps are exposed to vibration, because long-continued vibration sometimes causes the lamp to work. loose in the socket and iinally to fall out.

The object of my invention is to remedyv 2 5 this difficulty in a simple and effective manner, which shall not materially increase the cost of manufactu/ref'o'f the socket or lessen the simplicity of its construction.

To this end my invention mainly consists 3o in providing the interior of the Screw-threaded sleeve of the socket with a slightly-depressed tongue, which produces a sufficient friction or pressure on the lamp-base to prevent the lamp from working loose. I prefer to form 3 5 the sleeve with such a tongue by making in it a three-sided ont, which may be done with a saw, and slightly depressing the part cut, so that the same projects internally and forms a spring-tongue, which is curved and 4o screw-threaded like the rest of the sleeve, and does not interfere with the screwing in or out of the lamp, but produces sufficient pressureor friction to holdthe lamp from moving when in place.

45 My invention is illustrated in the accompanying drawings, in which` Figure l is an elevation of the interior parts of the lamp-Sockets, with the outer shell in section; Fig. 2, a top plan view of the 5o same, and Fig. 3 a vertical section of the screw-threaded sleeve on the line x of Fig. 2.

' The socket shown is of the ordinary character commonly used with the Edison lamp.

An insulating-base c has on its upper side a metal contact-plate b and a screw-threaded 55 Inetal sleeve c, secured to the base ct by means of a flange d. The binding-posts for making connection with the socket are shown at e e, and the whole is inclosed in a metal casing f, on whose lower end is secured a cap 6o g, the parts being held together by the screwthreaded ring h of insulating material. It will be understood that the lamp with which this socket is to be used is provided with a base, on whose lower end is a metal contact- 65 plate, and which is surrounded by a screwthreaded metal band. Such base being screwed into the sleeve c, the bottom plate of the lamp comes in contact with the plate b, and the circuit is completed through such plates 7o and through the screw-threaded sleeve and band. l make in the sleeve c a three-sided saw-cut at e' and Slightly depress the cut portion, as Inost clearly illustrated in Fig. 3, so that a curved and screw-threaded tongue 7c 75 is formed with its free end toward the top of the socket. lt will be seen that, as above eX- plained, such tongue does not interfere with the screwing in of the lamp, but it exerts sufficient pressure to retain t-he lamp securely 8o in place, and at the same time to materially improve the electrical contact between the lamp and socket.

lVhat l claim ifsl. In an electric-lamp socket, a screwL 8 5 threaded lamp-holding sleeve constituting a circuit-terminal, and provided with an inwardly-proj ecting tongue, substantially as described.

2. In an electric-lamp socket, a screw- 9o threaded lam p-supporting rin gprovided with an inwardly-extending springtongue, said ring forming one of the terminals of the electric circuit, substantially as described.

8. A socket which consists in a metal ring 9 5 screwthreaded and provided with an inwardly-extending tongue formed in the body of the ring, but not extending to the edge thereof, substantially as described.

This specification signed and witnessed this ioo 15th day of October, 1889.

JAMES J. BRADLEY.

lVitnesses:

WM. H. MEADOWOROET, CLARENCE T. VAN DEREN. 

